#include<stdio.h>
#include<math.h>
int main()
{
    float a,b,c,s,area;
    printf("Please enter three numbers:");
    scanf("%f%f%f",&a,&b,&c);
    s=(a+b+c)/2.0;
    area=sqrt(s*(s-a)*(s-b)*(s-c));
    
    if(a+b<=c||b+c<=a||a+c<=b)
    printf("False");
    else
    printf("The area is:%f",area);

    return 0;
}